1. Field of the Invention
The present invention relates to a dimmable operating device for lighting devices, which can be, for example, light-emitting diodes or gas discharge lamps.
2. Related Technology
For the purpose of issuing control commands to dimmable operating devices of a lighting installation, many of the currently employed lighting installations use a bus system, for example standardized by the DALI or DSI standard, by which inter alia external dimming values can be transmitted. The control devices required for controlling the individual lighting devices convert these values internally, for example with the aid of conversion tables, into dimming values that represent the actual stages of the brightness control of the connected lighting means, and that represent control values of possibly higher resolution (e.g. 16-bit quantized control values) than the external dimming values.
An operating device having a constant-current source as driver circuit for controlling an LED module comprising a plurality of light-emitting diodes is disclosed in DE 20 2004 006 292 U1. The driver circuit in that case is connected to the LED module via a total of three channels, of which two channels serve to supply voltage to the LED module with a voltage supply that is pulse-width-modulated in the dimming mode, and a third channel (“module identification channel”), realized as a digital interface, is used for the unidirectional or bidirectional transmission of digital operating parameters and/or calibration data between LED module and driver circuit, so that the driver circuit can set itself to these parameters and/or data. This makes it possible for LED modules of differing types to be operated with the same driver circuit, under the same operating conditions.
Described in EP 1 135 005 A2 is a circuit, controllable via a digital data interface, for controlling light sources of a lighting installation, which circuit has appropriate means for generating a control signal that is dependent on a predefinable setpoint value, for the purpose of controlling the brightness of the light sources, and has means for adapting the control signal to differing types of light source.
Disclosed in DE 203 12 298 U1 is an electronic control gear for operating a gas discharge lamp, which control gear comprises a memory device in which there are stored operating parameters that can be called up by a control device.